Indentation should be done with spaces, not with TABs, in the ARM subsystem

There are still a lot of old files in the QEMU ARM code base that use TABs for indentation instead of using 4 spaces in these files here:

 include/hw/arm/omap.h
 include/hw/arm/soc_dma.h
 include/hw/arm/sharpsl.h
 hw/intc/omap_intc.c
 hw/dma/omap_dma.c
 hw/gpio/omap_gpio.c
 hw/arm/omap1.c
 hw/arm/omap_sx1.c
 hw/arm/boot.c
 hw/misc/omap_clk.c
 hw/i2c/omap_i2c.c
 hw/timer/pxa2xx_timer.c
 tcg/arm/tcg-target.h

The TABs should be replaced, to make sure that we have a consistent coding style with an indentation of 4 spaces everywhere.